Stage collars for tubular strings



Nov. 9, 1965 J. c. WILLIAMS 3,216,452

STAGE COLLARS FOR TUBULAR STRINGS Original Filed June 29. 1961 .FI/0a la .F.'a CZ FGQ rraeA/Eys.

United States Patent Oice Patented Nov. 9, 1965 3,216,452 STAGE CDLLARS FR TUBULAR STRINGS James C. Williams, West Covina, Calif., assigner to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Continuation of application Ser. No. 120,658, .lune 29, 1961. This application Nov. 1, 1963, Ser. No. 321,727 17 Claims. '(Cl. 137-614.13)

This application is a continuation of my application for Stage Collars `for Tubular Strings, Serial No. 120,658, now abandoned, tiled June 29, 1961.

The present invention relates to apparatus adapted to be incorporated in a tubular string of casing, tubing, and the like, `to be lowered in a well bore, and through which fluent materials, such as cement slurry, can be pumped from the interior of the tubular string into the surrounding well bore annulus.

An object of the invention is to provide a ported stage collar for tubular lstrings to be disposed in a well bore and through which cementitious material can be pumped, in which opening and closing ofthe collar ports is secured by manipulating the tubular string, and in which such manipulation is easily controlled to assure the open and closed conditions of the ports.

Another object of the invention is to .provide a porte-d stage cementing collar to be incorporated in a tubular string in which the ports are opened :and closed by relative rotation between the collar ports, and in which the interior of the collar is in an essentially iiush condition after the ports have been reclosed, thereby avoiding gaps in the collar in which other equipment might subsequently snag or hang up `when lowered inthe tubular string.

A `further object of the invention is to -provde a ported stage cementing collar to be incorporated in a tubular string adapted to be lowered in a well bore, in which the collar ports are opened in response to manipulation of the tubular string, and in which no cement need remain in the tubular string and its collar after cement slurry has been discharged through the open ports, thereby obviating the need yfor -drilling out any cement from the interi-or of the tubular string and its collar.

This invention .possesses many other advantages, and has other objects which may be made more clearly apparent from a Iconsideration of a `form in which it may -be embodied. This yform is shown in the drawings accompanying and forming part of the present speciiication. It will n-ow be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the Aappended claims.

Referring -to the drawings:

`FIGURE 1 Vis a combined `side eleva-tional view and longitudinal section through an apparatus embodying the invention disposed in the well bore, with the collar ports in their initial closed condition;

FIG. 2 is a longitudinal section through the apparatus disclosed in FIG. l, -with the ports in open condition to allow the discharge of cement slurry therethrough;

FIG. 3 is a View similar to FIG. 2, lshowing the ports reclosed.

As disclosed in the drawings, a collar apparatus A is incorporated in a tubular string B disposed in a well bore C in which the tubular string is to be cemented. The apparatus is placed in the tubular string at an intermediate point along its length, such point being selected a required distance above the lower end of the tubular string. After the tubular string B has been lowered in the well bore C to the desired depth, cementitious material can be pumped down the tubular string for discharge through its `lower end or a `-lower point, after which ports in the collar apparatus A are opened so that an upper stage yof cementing can be performed through such collar ports, after which -they .are closed. The tubular string may be of relatively small size, consisting, for example, of sections of 2%; O.D. tubing, or it may be constituted as a string of casing, the sections of -which have a much greater diarneter than indicated.

The collar A `serves to connect lan upper portion 10 of the tubular string with a lower portion 11 of the tubular string. As specifically illustrated, the collar A includes an upper outer tubular member 12 having an upper threaded box 13 Afor threaded attachment to the lower pin end 14 of an adjacent upper tubing section 10. The collar Jfurther includes a lower inner tubular member 1S having a lower threaded pin 16 threadedly secured to a coupling 17, which is, in turn, threaded on to the upper pin end 18 of a lower tubing section 11 of the lower .portion of the tubular string. The outer tubular member 12 has a plurality of circumferentially spaced side ports 19 extending therethrough, there being internal right-hand threads 20 in the outer member below such ports, and an internal -cylindrical valve seat 21 above such ports. Above the valve seat 21, the outer member has a section 22 of enlarged internal diameter extending to the region of an external tapered valve seat 23 which inclines or converges in a downward and inward direction.

The lower inner tubular member 15 has an external or male thread 24 meshing with the internal thread 20'. The length of the threaded portion 24 of the inner member is substantially less than the length of the threaded portion 20 of the outer member 12, the inner member having a portion 25 of smaller external diameter above its threaded portion 24 spaced inwardly from the inner thread 20 and wall 22 of the outer member, as Well as inwardly of its cylindrical seat 21. Above its reduced diameter portion 25, the inner member has a valve head 26 of larger external diameter conforming to the diameter of the cylindrical seat 21 and adapted to sealingly engage such seat. To prevent leakage between the head 26 and seat 21 when these parts are coengaged, the head has a suitable side seal ring 27, such as a rubber or rubber-like O ring, disposed in a peripheral groove 28 and sealingly engaging against the cylindrical seat 21. The head 26 also has an internal tapered surface 29 conforming to the taper of the valve seat 23 of the outer member 12 and adapted to engage such valve seat. To assure leakproof engagement between the parts, a coating 30 of a relatively soft metal, such as bronze, is provided on the tapered head portion 29, which may be, for example, 1/15 of an inch thick. This coating 30 may be formed slightly convex, to assure its contact with the tapered seat 23 at a higher unit pressure, thereby assuring leakproof engagement between the head 26 and tapered seat 23.

The valve head 26 has a downwardly facing shoulder 31 disposed above a stop member 32, such as a stop screw threaded radially in the outer member 12 with its inner portion disposed under the head. Such'stop screw 32 limits the downward threading of the inner tubular member 15 within the outer tubular member 12 and is engaged by the head shoulder 31 to insure the disposition of the head 26 and its seal ring 27 within the cylindrical seat 21 in order to close the side ports 19 and prevent the passage of lluid between the interior and exterior of the collar through such ports. Initially, the parts are retained in the position closing the ports by one or a plurality of shear screws 33 threaded in the outer member 12 and into the valve head 26 of the inner member. If desired, in assembling the inner and outer members, the inner member 15 may be inserted upwardly into the outer member 12 and then threaded thereinto with the valve head 26 and seal ring 27 in appropriate engagement with the cylindrical seat 21, after which the stop screw 32 is threaded in the outer member and disposed under the stop shoulder 31. The inner member 15 may be unthreaded slightly relative to the outer member 12 until the shoulder 31 engages the stop screw 32, whereupon the hole for the shear screw may be drilled and tapped, after which the shear screw 33 is inserted in place. To facilitate relative threading between the inner and outer members 15, 12, bleeder ports 35 may be provided in the outer member below the side ports 19 and immediately above the threaded portion 24 of the inner member when the parts are in their initial position (FIG. l).

In the use of the apparatus A, its parts initially occupy the positions illustrated in FIG. 1, in which the side ports 19 are closed, the valve head 26 and -seal 27 being in engagement with the cylindrical seat 21, the stop screw 32 being disposed below the shoulder 31, with the shear screw 33 in place. The tubular string B with the collar A in its appropriate location along the length of the string is lowered in the well bore C to the desired depth. The Well bore may be appropriately conditioned by circulating uid down through the tubular string B and upwardly around lthe annulus D between the tubular string and wall of the well bore. If a lower stage of cementing is to be performed, the desired quantity of cement slurry is pumped down through the tubular string B and through the collar A, discharging at a lower point of the collar, such as from a lower shoe (not shown), the cement slurry rising in the annulus D to the location of the cementing collar A.

v After the cement deposited in the annulus around the lower portion 11 of the tubular string has had sufficient time to set, right-hand torque is imposed on the upper portion of the tubular string. The set cement will prevent turning of the lower portion of the tubular string and of the lower inner tubular member 15, so that theV application of sufficient right-hand torque to the upper portion 10 of the tubular string and the outer tubular member 12 will shear the screw or screws 33 and Will then cause the outer tubular member 12 to thread downwardly along the inner member 15 to a position opening the side ports 19, in which th cylindrical seat 21 is moved downwardly from engagement with the head 26. In a specific stage cementing collar that has been used, about three revolutions of the tubular string B and outer tubular member 12 are necessary to shift the outer tubular member 12 downwardly along the inner tubular member 15, or to the port opening position illustrated in FIG. 2.

A suiiicient quantity of cement slurry for performing the upper or second stage of cementing is now pumped down the tubular string B. Such cement slurry will pass laterally around the valve head 26 of the inner member and into the annular space between the valve head 26 and the outer member 12, flowing downwardly through such annular space and out through the open side ports 19 into the annulus D surrounding the tubular string, passing upwardly therethrough to the desired height. After substantially all of the cement slurry has been pumped out through the collar A, right-hand rotation of the upper portion 10 of the tubular string B and the outer member 12 is recommenced, which causes the outer tubular member 12 to feed downwardly of the inner member 15 to a further extent until the tapered valve seat 23 engages the metal sealing coated 30 on the tapered portion 29 of the valve head 26. When this occurs, the side ports 19 are closed and a metal-to-metal seal is secured between the inner and outer members 15, 12, precluding leakage therebetween.

With the parts in the position disclosed in FIG. 3, the collar ports 19 are closed and, ordinarily, such closed condition will be a permanent one. With the ports reclosed as shown in FIG. 3, the interior of the collar A is flush, as evidenced by the lack of any material gap between the inner and outer members 15, 12 when the valve head 26 engages the tapered seat 23. Accordingly, no space or gap exists into which other equipment subsequently lowered in the tubular string B might catch or hang up. The flush condition is achieved with an absence of any cementitious material within the collar A, or, for that matter, within the tubular string B above the collar, since appropriate measurements of the quantity of cement slurry displaced through the open ports 19 will insure that no cement slurry remains within the tubular string, requiring subsequent removal. The absence of cement within the tubular string is of importance, since it avoids the necessity for subsequently drilling out cement in the tubular string. Particularly where the tubular string B is of relatively small diameter, such as when it is composed of sections of tubing, it is difficult to drill such cement slurry out with the small size bits or cutters that must be used.

After the shear screw 33 has been disrupted, as the result of imposing torque on the tubular string B, the latter land the outer tubular member 12 might turn suddenly more than the desired number of revolutions, so that the condition 0f the collar is not definitely known with respect to the extent of opening of the ports 19 or their closing. Accordingly, after the shear screw has 'been disrupted, left-hand rotation is applied to the upper portion 1@ of the tubular string B and the outer member 12 until the head shoulder 31 engages the stop element or screw 32, which then assures the operator at the top of the well lbore that the collar is in the port closing position shown in FIG. 1. Thereafter, the upper portion 10 of the tubular string and the outer tubular member 12 can be rotated the proper number of turns to place the -parts in the position disclosed in FIG. 2 in which the side ports 19 are open. Rotation to the right is effected easily, inasmuch as the upper portion 10 of the tubular string and the outer tubular member 12 feed downwardly of the inner tubular mem-ber 15. Similarly, rotation of the upper portion of the tubular string -and of the outer tubular member to reclose the ports 19 is facilitated by the fact that the outer tubular member 12 moves downwardly along the inner tubular member 15 until the tapered seat 23 engages the metallic sealing material 30 at the upper end of the valve head 26 on the inner member. Sucient torque is applied to insure the proper compression of such sealing material 30 against the tapered valve seat 23, thereby avoiding leakage between the parts.

It is, accordingly, apparent that a relatively simple and economical stage cementing collar has been provided, 'which allows -a comparatively inexpensive stage cementing operation to be performed in that it is not necessary to drill out any cement that might remain in the tubular string after the cementing job has been performed. The reclosing of the side ports with the apparatus illustrated results in a smooth and ush inside bore in the cementing collar through which other tools, `such as swabs, can Ibe run safely without fear of their hanging up or being damaged.

I claim:

1. In apparatus for incorporation in a tubular string adapted to be disposed in a Well bore: an upper tubular member; a lower tubular member; one of said members being disposed within the other of said members; means on said members for securing them to adjacent upper and lower sections of the tubular string; one of said members having a Side port through wh-ich fluid may flow lbetween the interior and exterior of said members; coengaging means on said members axially to one side of said port for closing said port when said members are in a relatively extended iirst position; coengaging means on said members axially on said one side of said port for closing said port when said members are ina relatively contracted second position; and means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member lby the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and .5 rotation of said upper mem-ber by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position.

2. In app-aratus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular mem-ber having a Side port; a lower, inner tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; coengaging means on said members axially to one side of said port for closing said port when said members are in a relatively extended first position; coengaging means on said members axially on said one side of said port for closing said port when said members are in a relatively contracted second position; and means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member ldownwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other w-ith said members in s-aid first position, port opening position and second position.

3. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper tubular member; a lower tubular member; one of said members being disposed w-ithin the other of `said members; means on said members for securing them to adjacent upper and lower sections of the tubular string; one of said members having a side port through which fluid may flow between the interior and exterior of said members; one of said members having a pair of longitudinally lspaced valve seats thereon to one side of said port; means on the other of said members engaging one of said valve seats when said members are in a relatively extended first position to close said port and engaging the other of said Valve seats when said members are in a relatively contracted second position to close said port; and means on the other side of said port threadedly interconnect-ing said tubular members, whereby rotation of said upper member by the tu-bular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position.

4. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port; a lower, inner tubular member within said outer members; means on said members for securing them to ladjacent upper and lower sections of the tubular string; said outer member having a pair of longitudinally spaced valve seats thereon to one `side of said port; means on said inner member engaging one of said valve seats when said members are in -a relatively extended first position to close said port and engaging the other of said valve seats when said members are in a relatively contracted second position to close said port; and means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper, outer member by the tubular string relative to the lower, inner member feeds said upper member from sai-d first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds `said upper mem-ber downwardly of said lower member from said port opening position to said secon-d position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position.

5. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper tubular member; a lower tubular member; one of said members being disposed within the other of said members; means on said members for securing them to adjacent upper and 'lower sections of the tubular string; one of said members having a side port through which uid may iiow between the interior and exterior of said members; coengaging means on said members axially to one side of said port for closing said port when said members are in a relatively extended first position; coengaging means on said members axially on said one side of said port for closing said port when said members are in a relatively contracted second position; means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said iirst position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position; and coengageable stop means on said members limiting the extent of upward threaded movement of said upper member along said lower member beyond said first position.

6. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port; a lower, inner tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; coengaging means on said members axially to one side of said port for closing said port when said members are in a relatively extended irst position; coengaging means on said members axially on said one side of said port for closing said port when said members are in a relatively contracted second position; means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said rst position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position; and coengageable stop means on said members limiting the extent of upward threaded movement of said outer member along said inner member beyond said first position.

7. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port; a lower, inner tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a pair of longitudinally spaced valve seats thereon to one side of said port; means on said inner member engaging one of said valve seats when said members are in a relatively extended first position to close said port and engaging the other of said valve seats when said members are in a relatively contracted second position to close said port; means on the other side of said port threadedly interconnecting said tubular members, whereby rotation of said upper, outer member by the tubular string relative to the lower, inner member feeds said upper member from said first position downwardly of said lower member .to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position; and coengageable stop means on said members limiting the extent of upward threaded movement of said upper member along said lower member beyond said first position.

8. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an outer tubular member; an inner tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a port an-d a first cylindrical valve seat to one side of said port, said outer member having a second valve seat longitudinally spaced from said first valve seat and on said one side of said port; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position to close said port and engaging said second valve seat for closing said port when said members are in a relatively contracted second position; one of said members being an upper member and the other of said members a lower member; and means on the opposite side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position.

9. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port; a lower tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a first cylindrical Valve seat above said port and a second valve seat above and longitudinally spaced from said first valve seat; said inner member having a valve head engaging 'said first seat when said members are in a relatively extended first position to close said port and engaging said second valve seat when said members are in a relatively 'contracted second position to close said port; and means `below said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said 'lower member to a position opening said port and rotation of said upper member by the tubular string relative to 'said lower member then feeds said upper member downwardly of said lower member from said port opening posiltion to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position.

10. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an outer tubular fmember; an inner tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a port and a first cylindrical valve seat to one side of said port, said outer member having a second valve seat longitudinally spaced from said first valve seat and on said one side of said port; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position to close said port and engaging said second valve seat for closing said port when said members are in a relatively contracted second position; one of said members being an upper member and the other of said members a lower member; means on the opposite side of said port threadedly interconnecting said tubular members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position; and coengageable stop means on said members limiting the extent of upward threaded movement of said upper member along said lower member beyond said first position.

11. In apparatus for incorporation in a tubular string adapted to Ibe disposed in a well bore: an upper, outer tubular member having a side port; a lower tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a first cylindrical valve seat above said port and a second valve seat above and longitudinally spaced from said first Valve seat; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position -to close said port and engaging said second valve seat when said members are in a relatively contracted second position to close said port; means below said port threadedly interconnecting said tubular members, whereby rotation of said upper member bythe tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said interconnecting means threadedly securing said tubular members to each other with said members in said first position, port opening position and second position; and coengageable stop means on said members limiting the extent of upward threaded movement of said outer member along said inner member beyond said first position.

12. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an outer tubular member having a side port and an internally threaded portion to one side of said port, said outer member also having a first cylindrical Valve seat on the opposite side of said port and a second valve seat on said opposite side of said port longitudinally spaced from said first valve seat; an inner tubular member within said outer member; one of said members being an upper member and the other of said members a lower member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said inner member having a valve head engaging said first seat when said mem-bers are in a relatively extended first position to close said port and engaging said second seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to said lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said internal and external threads being in threaded mesh with each other to secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said valve head through said internally threaded portion into engagement with said first cylindrical valve seat.

13. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an outer tubular member having a side port and an internally threaded portion to one side of said port, said outer member also having a first cylindrical valve seat on the opposite side of said port and a second valve seat on said opposite side of said port longitudinally spaced from said iirst valve seat; an inner tubular member within said outer member; one of said members being an upper member and the other of said members a lower member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said inner member having a valve head engaging said rst seat when said members are in a relatively extended rst position to close said port and engaging said second seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to said lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second postion; said internal and external threads being in threaded mesh with each other to secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said valve head through said internally threaded portion into engagement with said first cylindrical valve seat; said inner member between its valve head and external thread having a lesser external diameter than the external diameter of said head to permit iiuid to flow between said irst cylindrical seat and inner member and into said port when said members `are in port opening position.

14. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port and an internally threaded portion below said port; a lower tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a first cylindrical valve seat above said port and a second valve seat above and longitudinally spaced from said first valve seat; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position to close said port and engaging said second Valve seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread below said head meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said external and internal threads being in mesh to secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said valve head through said internally threaded portion into engagement with said first cylindrical valve seat.

15. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port and an internally threaded portion below said port; a lower tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a iirst cylindrical valve seat above said port and a second valve seat above and longitudinally spaced from said first valve seat; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position to close said port and engaging said second valve seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread below said head meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said external and internal threads being in mesh to secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said valve head through said internally threaded portion into engagement with said iirst cylindrical valve seat; said inner member between its valve head and external thread having a lesser external diameter than the external diameter of said head to permit fluid to ow between said first cylindrical seat and inner member and into said port when said members are in port opening position.

16. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port and an internally threaded portion below said port; a lower tubular member within said outer member; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a rst cylindrical valve seat above said port and a second valve seat above and longitudinally spaced from said first valve seat; said inner member having a valve head engaging said first seat when said members are in a relatively extended iirst position to close said port and engaging said second valve seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread below said head meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said iirst position downwardly of said lower member to a position opening said port and rotation of said upper member by the tubular string relative to said lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said external and internal threads being in mesh to secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said valve head through said internally threaded portion into engagement with said first cylindrical valve seat; and stop means on said outer meml l ber engageable by the lower end of said valve head when said valve head engages said first seat.

17. In apparatus for incorporation in a tubular string adapted to be disposed in a well bore: an upper, outer tubular member having a side port and an internally threaded portion below said port; a lower tubular member within said outer mem-ber; means on said members for securing them to adjacent upper and lower sections of the tubular string; said outer member having a first cylindrical valve seat above said port and a second valve seat above and longitudinally spaced from said first valve seat; said inner member having a valve head engaging said first seat when said members are in a relatively extended first position to close said port and engaging said second lvalve seat when said members are in a relatively contracted second position to close said port; said inner member having an external thread below said head meshing with said internal thread to interconnect said members, whereby rotation of said upper member by the tubular string relative to the lower member feeds said upper member from said first position downwardly of said lower 'member to a position opening said port and rotation of said upper member by the tubular string relative to said -lower member then feeds said upper member downwardly of said lower member from said port opening position to said second position; said external and internal threads being in mesh to-secure said tubular members to each other with said members in said first position, port opening position, and second position; said valve head having a lesser diameter than the internal diameter of said internally threaded portion to permit insertion of said Valve head through said internally threaded portion into engagement with said first cylindrical valve seat; said inner member between its valve head and external thread having a lesser external diameter than the external diameter of said head to permit fluid to flow between said first cylindrical seat and inner member and into said port when said members are in port opening position; and stop means on said outer member engageable by the lower end of said valve head when said valve head engages said first seat.

References Cited by the Examiner UNITED STATES PATENTS 2,196,664 4/40 Kofahl 251-347 XR 2,214,555 9/40 Hayward 251-343 2,275,938 3/ 42 Baker 251-347 XR 2,509,470 5/50 Baker 251-341 XR 2,630,999 3/53 Lee 251-347 XR 2,631,000 3/53 Lee 251-343 2,663,307 12/53 Birdwell 251-343 XR WILLIAM F. ODEA, Primary Examiner. 

1. IN APPARATUS FOR INCORPORATION IN A TUBULAR STRING ADAPTED TO BE DISPOSED IN A WELL BORE: AN UPPER TUBULAR MEMBER; A LOWER TUBULAR MEMBER; ONE OF SAID MEMBERS BEING DISPOSED WITHIN THE OTHER SAID MEMBERS; MEANS ON SAID MEMBERS FOR SECURING THEM TO ADJACENT UPPER AND LOWER SECTIONS OF THE TUBULAR STRING; ONE OF SAID MEMBERS HAVING A SIDE PORT THROUGH WHICH FLUID MAY FLOW BETWEEN THE INTERIOR AND EXTERIOR OF SAID MEMBERS; COENGAGING MEANS ON SAID MEMBERS AXIALLY TO ONE SIDE OF SAID PORT FOR CLOSING SAID PORT WHEN SAID MEMBERS ARE IN A RELATIVELY EXTENDED FIRST POSITION; COENGAGING MEANS ON SAID MEMBERS AXIALLY ON SAID ONE SIDE OF SAID PORT FOR CLOSING SAID PORT WHEN SAID MEMBERS ARE IN A RELATIVELY CONTRACTED SECOND POSITION; AND MEANS ON THE OTHER SIDE OF SAID PORT THEREDABLY INTERCONNECTING SAID TUBULAR MEMBERS, WHEREBY ROTATION OF SAID UPPER MEMBER BY THE TUBULAR STRING RELATIVE TO THE LOWER MEMBER FEEDS SAID UPPER MEMBER FROM SAID FIRST POSITION DOWNWARDLY OF SAID LOWER MEMBER TO A POSITION OPENING SAID PORT AND ROTATION OF SAID UPPER MEMBER BY THE TUBULAR STRING RELATIVE TO SAID LOWER MEMBER THEN FEEDS SAID UPPER 